Should I go back to the cardiologist?
You should definitely see a doctor, but it does not have to be a cardiologist. They symptoms you describe are consistent with anxiety although heart symptoms can sometimes sound like anxiety also. If the symptoms are exactly the same, it is probably the same cause as before.
Could there be something wrong, or is it probably anxiety
Probably anxiety, but your doctor should help you decide on this. Please don't self diagnosis. That can be dangerous.
How long can you have pain before a heart attack occurs.
If it is true
cardiacCardiac catheterization
Cardiac tamponade
Left heart ventricular angiography pain, the heart attack often occurs with the pain. Heart injury can occur within minutes. Since this is the internet, I can't really tell you if your pain is cardiac. You should call your doctor's office and talk to the doctor on call to help you decide how to handle it.
I hope this helps. Thanks for posting.